Adjustable pressure regulating valve for fuel injection systems

ABSTRACT

A fuel injection system for internal combustion engines includes including a high-pressure reservoir which is acted upon by fuel at high pressure via a high-pressure feed unit and supplies fuel injectors with fuel. The high-pressure feed unit is assigned a pressure regulating valve which is disposed between a high-pressure side and a low-pressure side and includes a valve element which is triggerable via an electrical final control element. The pressure regulating valve includes a housing component which includes a deformable region by way of which, upon mounting of the pressure regulating valve on a receiving body, a gap L between faces of an electrically triggerable final control element assembly is adjustable.

FIELD OF THE INVENTION

In self-igniting internal combustion engines, besides unit fuelinjectors and pump-line-nozzle systems, reservoir-type injection systemsare used for injecting fuel. These injection systems include ahigh-pressure reservoir, which is supplied with fuel at high pressurevia a high-pressure pump. The high-pressure pump represents theinterface between the high-pressure and low-pressure parts of theinjection system. The high-pressure pump includes a pressure regulatingvalve, which serves on the one hand to open at excessively high pressurein the high-pressure reservoir, so that fuel flows out of thehigh-pressure reservoir back to the fuel tank via a collection line, andon the other, at excessively low pressure in the high-pressurereservoir, to seal off the high-pressure side from the low-pressureside.

BACKGROUND OF THE INVENTION

From the publication entitled “Dieselmotor-Management” [Diesel EngineManagement], 2nd, Updated and Expanded Edition, Vieweg 1998,Braunschweig and Wiesbaden, ISBN 3-528-03873-X, page 270, FIG. 9, apressure regulating valve is known. The pressure regulating valve isused in a high-pressure pump; see page 267, FIG. 7, of the samepublication. The pressure regulating valve includes a ball valve, whichincludes a spherical closing body. Received inside the pressureregulating valve is an armature, which on the one hand is acted upon bya compression spring and on the other has an electromagnet disposedopposite it. The armature of the pressure regulating valve is bathedwith fuel for the sake of lubrication and cooling.

If the pressure regulating valve is not triggered, then the highpressure prevailing in the high-pressure reservoir or at the outlet ofthe high-pressure pump is present at the pressure regulating valve viathe high-pressure inlet. Since the currentless electromagnet does notexert any force, the high-pressure force predominates over the springforce of the compression spring, so that the pressure regulating valveopens, and depending on the fuel quantity pumped remains more or lesswidely open.

Conversely, if the pressure regulating valve is triggered, that is, ifcurrent is supplied to the electromagnet, then the pressure in thehigh-pressure circuit is increased. To that end, a magnetic force isgenerated, in addition to the force exerted by the compression spring.The pressure regulating valve is closed until a force equilibriumprevails between the high-pressure force on the one hand and both thespring force and the magnet force on the other. The magnetic force ofthe electromagnet is proportional to the triggering current I of themagnet coils inside the pressure regulating valve. The triggeringcurrent I can be varied by means of clocking (pulse width modulation).

According to the aforementioned publication, page 270, FIG. 7, thepressure regulating valve is screwed into the high-pressure pump, forinstance. The problem then arises that the requisite exactcharacteristic curve p=f(I), where I stands for the triggering currentof the electromagnet, and where Q*=const., is dependent essentially onthe air gap L that is established between the armature plate and themagnet core in which the magnet coils of the electromagnet are received.Upon mounting of the pressure regulating valve in a receiving body, inthis case a high-pressure pump, for instance, the air gap L is adjusted.Depending on the air gap L, the characteristic curve of the pressureregulating valve, p=f(I), is established. The required tolerance in theaforementioned characteristic curve p=f(I) of the pressure regulatingvalve is adjusted at a test point, which is defined by a selected valuefor the triggering current I of the coils of the electromagnet. At thistest point, a pressure tolerance of ±Δp of the pressure regulating valveis ascertained. The lower this tolerance proves to be, the better theattainable quality of regulation is in terms of the triggering behaviorof the pressure regulating valve, and the more precisely the pressureregulating valve responds to pressure fluctuations between thehigh-pressure side and the low-pressure side.

Since the air gap L is dependent on the mounting quality and in theprocedure of the prior art can be adjusted only at major effort, thepressure tolerance ±Δp established at the test point depends to aconsiderable degree on the quality of the mounting of the pressureregulating valve on a high-pressure pump, or on some other partsubjected to high pressure.

SUMMARY OF THE INVENTION

The advantage of the embodiment proposed according to the invention isabove all that in designing a housing body of the pressure regulatingvalve with an intentionally weakened region, that is, a component regiondesigned to be softer, an elastic and/or plastic deformation can bebrought about intentionally upon mounting of the pressure regulatingvalve in a high-pressure pump or a high-pressure reservoir. With ahousing body of a pressure regulating valve that has a region that iselastically and/or plastically deformable, the air gap L in the magnetsystem comprising the armature plate and magnet core can be adjustedintentionally or changed intentionally. The adjustment or change in theair gap L can be predetermined via the mounting force, for instance byway of the mounting torque to be exerted. Once the air gap L is adjustedwithin the magnet system, the pressure tolerances at the test point thatresult from the component tolerances can be minimized, for apredetermined triggering current I for the magnet coils of theelectromagnet.

As a result, economical components that involve relatively greatcomponent tolerances can be used, since their component tolerances canbe equalized upon mounting of the components with a well-definedmounting force, such as a maximum allowable mounting torque.

By changing the air gap L in the magnet system by means of a deformableregion of a pressure regulating valve that can be acted upon by adefined mounting force, a previously high pressure tolerance ±Δp can bereduced by a mounting force to the requisite pressure tolerance ±Δp.Thus a more-stable control characteristic of a fuel injection systemwith a high-pressure reservoir (common rail) can be attained. On theother hand, the embodiment proposed according to the invention assuressimpler mounting of a pressure regulating valve on a high-pressure pumpor a high-pressure reservoir, since the mounting of the pressureregulating valve on one of these components is less dependent onindividual skill, and thus the production rate in large-scale massproduction of injection systems or injection system components can beincreased considerably.

DRAWING

The embodiment according to the invention will be described in furtherdetail below in conjunction with the drawing.

Shown are:

FIG. 1, the components of a fuel injection system with a high-pressurereservoir; and

FIG. 2, the pressure regulating valve, shown in section on a largerscale, integrated with a high-pressure-carrying component, such as ahigh-pressure pump or a high-pressure reservoir.

VARIANT EMBODIMENTS

FIG. 1 shows the components of a high-pressure injection system with ahigh-pressure reservoir (common rail).

The fuel injection system 1 shown in FIG. 1 includes a fuel tank 2, inwhich fuel is located, as indicated by a fuel level 3. A prefilter 4,preceded by a prefeed unit 5, is disposed below the level of the fuelinside the fuel tank 2. The prefeed unit 5 pumps the fuel, aspirated viathe prefilter 4, out of the fuel tank 2 via a fuel filter 6 into alow-pressure line portion 7 that discharges into a high-pressure feedunit 8. The high-pressure feed unit 8, which can for instance be ahigh-pressure pump, is triggered via a trigger line 9 by a centralcontrol unit 14, shown only schematically here. Besides the terminal forthe low-pressure line connection 7, the high-pressure feed unit 8includes a pressure regulating valve 12 with an electrical terminal 14that is likewise via a triggering means 13, triggered via the centralcontrol unit 14. A high-pressure inlet branches off from thehigh-pressure feed unit 8 and by way of it a tubular high-pressurereservoir 15 is subjected to fuel that is at high pressure. A fuelreturn line 11 also branches off from the high-pressure feed unit 8 anddischarges into a return 17 which in turn carries excess outflowing fuelback into the fuel tank 2.

The fuel, at very high pressure, pumped via the high-pressure inlet 10by the high-pressure feed unit 8 enters the high-pressure reservoir 15(common rail), on the outer circumference of which a pressure sensor 16is received. The pressure sensor 16 is in turn in communication, via apressure signal line 25, with a central signal transmission line 24,which in turn also extends outward beginning at the control unit 14.From the high-pressure reservoir 15, which may for instance be embodiedas a tubular component on the order of a forged part, high-pressurelines 18 branch off, in a number corresponding to the number of fuelinjectors 19. The high-pressure lines 18 discharge at the respectiveinlet connection 20 of the injector bodies of the fuel injectors 19. Thefuel injectors 19 include actuators, which may for instance be in theform of piezoelectric actuators, mechanical-hydraulic boosters, ormagnet valves and which initiate the injection events in appropriateorder. The actuators of the individual fuel injectors 19, via actuatortriggering lines 22, likewise communicate with the central signaltransmission line 24, which begins at the schematically shown centralcontrol unit 14. The individual fuel injectors 19 also have return lines21, which likewise discharge into the aforementioned return 17 to thefuel tank 1, so that control volumes to be diverted, for instance, canflow out into the fuel tank 2.

Besides the aforementioned triggering line 13 for triggering anelectromagnet contained in the pressure regulating valve 12 and atriggering line 9 for the high-pressure feed unit 8 as well as apressure sensor line 25 to the pressure sensor 16 of the high-pressurereservoir 15, a triggering line 26 with which the prefeed unit 5accommodated in the fuel tank 2 can be triggered also branches off fromthe control unit 14. The central control unit 14 of the fuel injectionsystem furthermore receives signals from a crankshaft sensor, whichserves to detect the rotary position of the engine, as well as signalsfrom a camshaft sensor 28, by way of which the corresponding phaserelationship of the engine can be determined, as well as input signalsfrom an accelerator pedal sensor 29. In addition, the central controlunit 14, via the central signal transmission line 24, receives signalsthat characterize the charge pressure 30, via a corresponding sensoraccommodated in the intake tract of the engine. Furthermore, the enginetemperature 31, detected for instance at the walls of the combustionchambers of the engine, and the temperature 32 of the coolant fluid areforwarded to the central control unit 14, shown schematically in FIG. 1,via the central control line 24.

FIG. 2, in longitudinal section on a larger scale, shows theconfiguration according to the invention of the pressure regulatingvalve, which is built into a high-pressure-carrying component, whetherit is a high-pressure feed unit or a high-pressure reservoir.

It can be seen from the view shown in FIG. 2 that the pressureregulating valve 12 includes an electrical terminal 40, by way of whichan electrically triggerable final control element disposed in thepressure regulating valve 12 can be activated and deactivated.

The electrical final control element, in the variant embodimentaccording to the invention shown in FIG. 2, is embodied as anelectromagnetic final control element. An armature bore 40 is providedin a housing component 41 of the pressure regulating valve 12 and ispenetrated by an armature part 45. An armature plate 46 is received onone end of the armature part 45. The armature plate 46 is acted upon, onits connection end, by a compression spring element 44. The compressionspring element 44 and the outer circumferential surface of the armatureplate 46 are surrounded by a bell-shaped insert 42, which is likewisereceived in the housing component 41 of the pressure regulating valve12. Opposite one face end 48 of the armature plate 46, an electromagnet47 is let into the housing component 41 of the pressure regulating valve12. An air gap L is adjusted between the face end 48 of the armatureplate 46 and one face end 41 of the housing component 41.

The housing component 41 of the pressure regulating valve 12 issurrounded by a mounting element 51. In the view shown in FIG. 2, themounting element 51 is received rotatably on the outer circumferentialsurface of the housing component 41. In the axial direction, relative tothe housing component 41, the mounting element 51 is supported on asupport ring 65 that is received in the narrowed-diameter region of thehousing component 41. As shown, the mounting element 51 may be embodiedas a mounting screw, which includes a male thread that can be screwedinto a corresponding thread on a receiving body 8 or 15 in which thepressure regulating valve 12 is secured. The receiving body 8 and 15 mayfor instance be the high-pressure feed unit 8 shown in FIG. 1 or thehigh-pressure reservoir (common rail) identified by reference numeral15. A well-defined tightening torque can be introduced into the mountingelement 51, with which torque the housing component 41 of the pressureregulating valve 12 is screwed into the receiving body 8 or 15.

The armature part 45 of the electrical final control element, with itsend opposite the armature plates 46, acts upon a closing element 54,here embodied as a valve ball, embodied spherically in the view of thepressure regulating valve shown in FIG. 2. The valve ball 54 is moved bymeans of the armature part 45 of the electrically triggerable finalcontrol element into a seat 55 which is embodied on a seat ring 64. Theseat ring 64 is surrounded by the housing component 41, with theinterposition of a disklike spacer element 63. The valve element 54,embodied spherically in the view of FIG. 2, closes a through bore,functioning as a throttle, of the seat ring 64. The seat ring 64, whoseouter circumferential surface is surrounded by the housing component 41of the pressure regulating valve 12, is acted upon, on the side oppositethe closing element 54, by the system pressure prevailing in a hollowchamber 56. Upon actuation of the armature part 45 of the electricallytriggerable final control element of the pressure regulating valve 12,the through bore that can be closed and opened by the valve element 54acts inside the seat ring 64 as an outlet throttle with regard to thehigh pressure prevailing in the receiving body 8 or 15. The latter canbe relieved, upon actuation of the armature part 45, via the outletthrottle, embodied as a through bore, into the low-pressure part 11,from which low-pressure lines 53 extending perpendicular to the axis ofthe armature part 45 in the receiving body 8, 15 branch off, these linesin turn communicating with the fuel return 11 (see the view in FIG. 1).

The view in FIG. 2 also shows that the housing component 41 of thepressure regulating valve 12, on its end opposite the electricalterminal 40, includes a deformable region 57. The deformable region 57extends along an axial length 61 between a sealing element 62, receivedon the circumferential face of the housing component 41, and thedisklike element 63, which is likewise surrounded by the housingcomponent 41 of the pressure regulating valve 12. Within this axiallength 61, the armature bore 50, which is penetrated by the armaturepart 45 of the electrical final control element, is surrounded by ahollow chamber. Bores extending perpendicular to the axis of thearmature bore 50 are disposed in the hollow chamber wall and are alignedwith the low-pressure bores 53 in the receiving body 8, 15. Thedeformable region 57 extending over the axial length 61 can be designedas intentionally weakened, so that upon mounting of the housingcomponent 41 of the pressure regulating valve 12 in the receiving body 8or 15, a plastic or elastic deformation of the deformable region 57ensures. The weakening inside the deformable region 57 can also bedimensioned such that upon mounting of the housing component 41 of thepressure regulating valve 12, an elastic and a plastic deformation ofthe region 57 ensue. It can be seen from FIG. 2 that the wall of thehousing component 41 can be embodied with a reduced wall thicknesswithin the axial length 61. Reference numeral 59 indicates a first wallthickness which is reduced considerably in the region of the mountingelement 51, in comparison to the wall thickness between the armaturebore 50 and the outer circumferential surface of the housing component41. In addition, it is entirely possible instead to embody the wallthickness 59.1, in comparison to the aforementioned wall thickness 59,as a wall thickness exceeding the latter, as shown in FIG. 2. The wallthickness 59.1 as shown in FIG. 2 exceeds the wall thickness 59, butassures that upon mounting of the housing component 41 of the pressureregulating valve 12 in the receiving body 8 or 15, an elastic or plasticdeformation of the deformable region 57 is assured. Besides a weakeningof the wall by reducing the wall thickness to a wall thickness 59 or59.1 in FIG. 2, through openings 60 may also be disposed within thedeformable region. Depending on the number of through openings 60 andtheir disposition relative to the circumferential surface of thedeformable region 57 of an axial length 61 on the outer circumference ofthe housing component 41, the degree of deformability of the deformableregion 57 of the housing component 41 can be varied. The throughopenings 60 shown in FIG. 2 may also be embodied as through bores;however, it is equally possible to embody the openings 60 as blindbores, so that a deformability of the housing component 41 that variesin the radial direction can be attained upon the mounting of the housingcomponent on the receiving body 8 or 15. It is equally possible toembody the deformable region 57 on the end of the housing component 41of the pressure regulating valve 12 opposite the connection end with acombined wall weakening, with through openings 60 disposed in thisweakened wall zone. In this way, an especially soft deformation region57 can be attained whose elastic deformability changes over into aplastic deformation when a defined mounting torque is brought to bear.

Besides an embodiment of the deformable region 57 on the housingcomponent 41 of the pressure regulating valve 12 by making a wallweakening 59 or 59.1 and/or disposing through openings 60 along thecircumferential surface of the deformable region 57 on the housingcomponent 41, it is also possible to embody the deformable region 57 onit in the form of a Z-shaped profile section, or concertina shape. Theadjustment of the air gap L upon mounting of the pressure regulatingvalve 12 in the receiving body 8, 15 is effected as described below:

The housing component 41 of the pressure regulating valve 12 is firstscrewed into the female thread in the bore in the receiving body 8 or 15by means of the mounting element 51 embodied as a mounting screw. Afterthat, a torque can be introduced at the mounting element 51 in a simpleway, and with it the housing component 41 is prestressed in thereceiving body 8. The axial motion of the housing component 41 isassured by the fact that the mounting element 51, embodied as a mountingscrew, is braced on the outer circumferential surface of the housingcomponent 41, on a support ring 65 let into the housing component. Thisassures that upon tightening of the mounting element 51, the housingcomponent 41 is prestressed against the receiving body 8 or 15. When thehousing component 41 is screwed in, the disklike intermediate element 63presses against an end face of the housing component 41. The seat ring64, which is provided with a throttle restriction acting as an outletthrottle, presses against the receiving body 8 or 15. On the opposite,connection end of the housing component 41, an air gap L is establishedbetween the face end 48 of the armature plate 46, oriented toward theelectromagnet 47, and the face end 49 of the housing component 41. Sincethe air gap L is dependent on the position of the armature plate 46relative to the face end 49 of the housing component 41, and the tip ofthe armature part 45 touches the closing element 54, which is receivedin the seat 55 of the seat ring 64, an air gap L between the face end 58of the armature plate 46 and the face end 49 of the housing component 41is established, depending on the mounting torque. In this state, an airgap L prevails that is determined only by the tightening torque of themounting element 51. Varying the air gap L can be done by having themounting force 58—represented by the arrows pointing toward one anotherin FIG. 2—bringing about a deformation, either plastic, elastic and/orplastic and elastic, of the deformable region 57 on the housingcomponent 41 upon further action upon the mounting element 51. As aresult of the design of the wall thickness reduction 59 and 59.1 inaccordance with the axial length 61 of the deformable region 57, theresultant deformation is dependent on the magnitude of the tighteningtorque brought to bear on the mounting element 51. Because of the designof the deformable region 57, whether it is with through openings 60,with blind bores along the circumference, a first reduction in the wallthickness (see reference numeral 59), or a second reduction in the wallthickness (see reference numeral 59.1), the degree of deformation of thedeformable region 64 on the housing component 41 can be defined. Becauseof the known tightening torque and the known deformation behavior of thedeformable region 57 on the housing component 41, the result is anexactly defined air gap L between the face end 48 of the armature plate46 and the face end 49 of the housing component 41. Depending on themounting tightening moment brought to bear at the mounting element 51and the result deformation of the deformable region 57, the air gap L ofthe electrical final control element, in this case embodied as anelectromagnet, can be varied. Once the air gap L has been adjusted, theelectrical terminal 40 is simply clipped onto the circumferentialsurface of the pressure regulating valve, on the connection end of thehousing component 41 of the pressure regulating valve 12.

In the mounted state of the pressure regulating valve 12 on a receivingbody 8 or 15, whether this is a high-pressure feed unit 8 or ahigh-pressure reservoir 15, the air gap L between the face end 48 of thearmature plate 46 and the face end 49 of the housing component 41 isadjusted by the mounting force 58 and the deformability of thedeformable region 57. Thus with the imposition of a triggering currentI, the pressure tolerance ±Δp of the pressure regulating valve 12 can beadjusted in a simple way at a defined test point, which is defined by adefined triggering current I of the electromagnet 47. If the requisitetolerance at the test point is not attained, then by varying thetightening force of the mounting element 51 and a resultant change inthe deformation of the deformable region 57 of the housing component 41,the air gap L can be varied relative to one another at the magnetcomponent. Changing the air gap L is thus a direct consequence of themounting force 58 exerted upon mounting by the mounting element 51,which in turn determines the deformability of the deformable region 57on the end of the housing component 41 opposite its connection end. Withthe embodiment proposed according to the invention of the housingcomponent 41, including a deformable region 57, economical componentswith relatively great tolerances can be used. The great tolerances, whenthe mounting force 58 is exerted—for instance in the present case in theform of a mounting torque to which the mounting element 51 issubjected—are brought virtually to zero by the resultant mounting force58. The air gap L between the armature plate 46 and the face end of thehousing component 41 of the pressure regulating valve 12 is establishedonly upon a further increase in the mounting force 58, accordingly afterthe time at which the component tolerances have already been equalized.Because of a further, well-defined increase in the mounting force 48,the deformation within the deformable region 57 of the housing component41 that varies the air gap L is established.

On the end of the armature part 45 opposite the seat ring 64, inside thehousing component 41, a hollow chamber is embodied. Low-pressure bores53 branch off from this hollow chamber perpendicular to the armaturebore 50 that is penetrated by the armature part 45. When the closingelement 54 is opened as a result of triggering of the armature part 45,the closing element 54, here embodied spherically, uncovers the throttlerestriction embodied in the seat ring 64 and acting as an outletthrottle, so that fuel at high pressure from the hollow chamber 56,acted upon by system pressure, of the receiving body 8 or 15, into whichthe pressure regulating valve 12 is screwed with its housing component41, can flow out from the high-pressure area into the low-pressure area11 or 53.

LIST OF REFERENCE NUMERALS

-   1 Fuel injection system-   2 Fuel tank-   3 Fuel level-   4 Prefilter-   5 Prefeed unit-   6 Fuel filter-   7 Low-pressure line portion-   8 High-pressure feed unit-   9 Trigger line-   10 High-pressure inlet-   11 Fuel return-   12 Pressure regulating valve-   13 Triggering of electromagnet-   14 Control unit-   15 High-pressure reservoir-   16 Pressure sensor-   17 Return to fuel tank-   18 High-pressure supply line to injector-   19 Fuel injector-   20 Inlet side-   21 Return from fuel injector-   22 Actuator triggering-   23 Injection nozzles-   24 Central signal transmission line-   25 Pressure sensor line-   26 Triggering of prefeed pump-   27 Crankshaft sensor-   28 Camshaft sensor-   29 Accelerator pedal sensor-   30 Charge pressure sensor-   31 Temperature sensor-   32 Coolant sensor-   40 Electrical terminal-   41 Housing component of pressure regulating valve-   42 Bell-shaped insert-   43 Sealing ring-   44 Compression spring-   45 Armature part-   46 Armature plate-   47 Electromagnet-   48 Face end of armature plate-   49 Face end of housing component-   50 Armature bore-   51 Mounting element-   52 Receiving body of pressure regulating valve 12-   53 Low-pressure line-   54 Valve ball-   55 Valve ball seat-   56 Hollow chamber with system pressure-   57 Deformable region-   58 Action direction of mounting force-   59 First reduced wall thickness-   59.1 Second reduced wall thickness-   60 Weakening opening-   61 Axial length of deformable region-   62 Sealing element-   63 Disklike insert-   64 Seat ring with throttle opening-   65 Support ring-   L Air gap of magnet system

1-14. (canceled)
 15. In a fuel injection system for internal combustionengines, having a high-pressure reservoir (15), which is subjected tofuel at high pressure via a high-pressure feed unit (8) and suppliesfuel injectors (19) with fuel, and the high-pressure feed unit (8) isassigned a pressure regulating valve (12) which is disposed between ahigh-pressure side (10, 56) and a low-pressure side (11, 53) andincludes a valve element (54), which is triggerable via an electricalfinal control element (47), the improvement wherein the pressureregulating valve (12) comprises a housing component (41), which includesa deformable region (57) by way of which upon mounting of the pressureregulating valve (12) on a receiving body (52) that carries highpressure, a gap L between faces (48, 49) of an electrically triggerablefinal control element assembly (45, 47) is adjustable.
 16. The fuelinjection system of claim 15, wherein the housing component (41) of thepressure regulating valve (12) that includes the deformable region (57)is embodied as a housing body.
 17. The fuel injection system of claim16, wherein the deformable region (57) on the housing component (41) islocated in a region which in the mounted state of the pressureregulating valve (12) on a receiving body (52) is surrounded by thereceiving body.
 18. The fuel injection system of claim 16, wherein thehousing component (41) comprises a mounting element (51) that is movablerelative to the outside of the housing component.
 19. The fuel injectionsystem of claim 15, wherein the deformable region (57) on the housingcomponent (41) of the pressure regulating valve (12) is formed by a wallthickness reduction (59, 59.1).
 20. The fuel injection system of claim15, wherein the deformable region (57) on the housing component (41) ofthe pressure regulating valve (12) is formed by recesses (60) orientedperpendicular to the action line (58) of the mounting force.
 21. Thefuel injection system of claim 20, wherein the recesses (60) areembodied as through bores.
 22. The fuel injection system of claim 20,wherein the recesses (60) are embodied as blind bores.
 23. The fuelinjection system of claim 18, wherein the mounting element (51) issecured in the axial direction on the outside of the housing component(41) of the pressure regulating valve (12) by a support ring (65). 24.The fuel injection system of claim 15, further comprising an armatureplate (46) acted upon by a spring element (44), the armature plate (46)being disposed on the connection end of the housing component (41) ofthe pressure regulating valve (12), and an air gap L formed between theface end (48) of the armature plate and a face end (49) of the housingcomponent (41) that surrounds an electromagnet (47).
 25. The fuelinjection system of claim 15, further comprising a seat ring (64) thathas a valve seat (55) for the valve element (54), the housing component(41) of the pressure regulating valve (12), on the end toward the valve,surrounding the ring seat.
 26. The fuel injection system of claim 25,wherein the seat ring (64) comprises a throttle restriction, whichserves on the high side as an outlet throttle with respect to the systempressure inside a hollow chamber (46) of the receiving body (52) andwhich can be opened and closed by the valve element (54).
 27. The fuelinjection system of claim 25, wherein the deformable region (57) of thehousing component (41) extends in the axial direction (61) between asealing element (62) and the seat ring (64).
 28. The fuel injectionsystem of claim 1, wherein the deformable region (57) of the housingcomponent (41) of the pressure regulating valve (12) is elastic and/orplastic, depending on the mounting force (58) brought to bear at themounting element (51).